To meet the demand for wireless data traffic having increased since deployment of 4G communication systems, efforts have been made to develop an improved 5G or pre-5G communication system. Therefore, the 5G or pre-5G communication system is also called a ‘Beyond 4G Network’ or a ‘Post LTE System’.
The 5G communication system is considered to be implemented in higher frequency (mmWave) bands, e.g., 60 GHz bands, so as to accomplish higher data rates. To decrease propagation loss of the radio waves and increase the transmission distance, the beamforming, massive multiple-input multiple-output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna, an analog beam forming, large scale antenna techniques are discussed in 5G communication systems.
In addition, in 5G communication systems, development for system network improvement is under way based on advanced small cells, cloud Radio Access Networks (RANs), ultra-dense networks, device-to-device (D2D) communication, wireless backhaul, moving network, cooperative communication, Coordinated Multi-Points (CoMP), reception-end interference cancellation and the like.
In the 5G system, Hybrid FSK and QAM Modulation (FQAM) and sliding window superposition coding (SWSC) as an advanced coding modulation (ACM), and filter bank multi carrier (FBMC), non-orthogonal multiple access (NOMA), and sparse code multiple access (SCMA) as an advanced access technology have been developed.
In general, communication between devices is achieved via an Access Point (AP) in a wireless Local Area Network (LAN) system, Recently, however, devices for performing communication are diversified, and a method of performing direct communication between the devices without the aid of the AP has been developed to effectively use a radio resource. This is referred to as a peer to peer (P2P) mechanism, a device to device (D2D) mechanism, and the like.
If the devices directly communicate with each other, the communication may be achieved through a specific channel. Optionally, the communication may be maintained while changing the channel. In general, if the direct communication is achieved between two devices, a procedure of establishing an initial connection between the two devices includes a process of finding peer devices in the specific channel, a process of predetermining a channel through which data is exchanged, and a process of changing a channel to the channel pre-determined to exchange the data.
If a frequency characteristic is similar between a channel to which the two devices are connected before channel changing and a channel which is changed to exchange data in practice, a possibility that a connection between the two devices fails in the changed channel is very low. However, the frequency characteristic may be different between the channel to which the two devices are connected before channel changing and the channel which is changed to exchange data. In this case, even if the connection is completely achieved between the two devices before the channel changing, there is a high possibility that the connection in the changed channel fails since a channel characteristic after the changing is different from that of the existing channel.